Cell and Tissue Journal

Abstract Aim: The purpose of the present research project was evaluation of the effect of silicon on the severity of peroxidase genes expression and some morphological traits in both resistant and susceptible barley lines under drought stress. Material and Methods: Total soluble protein content, photosynthetic pigments, and total RNA were extracted from the leaves affected by various treatments. Target gene was evaluated by Semi-quantitative RT-PCR analysis using synthesized cDNA. Both the peroxidase enzyme activity by Chance method and proline with Bates method were also evaluated under drought stress treatment. Accordingly, the experiment was analyzed in a factorial test based on the completely randomized design with three treatments of control, drought and silicon-drought (sodium silicate 2 mg / 1 Kg soil) with three replications in a greenhouse. Results: Silicon application caused to increase the amount of total soluble protein and photosynthetic pigments in both lines under drought stress. Semi-quantitative RT-PCR analysis of treatments observed significant differences. Maximum of peroxidase gene expression was observed in the silicon-drought treatment. Antioxidant enzyme activities were at the highest level as shown by gene expression pattern of polyacrylamide gel analysis for treated silicon samples. A further increase was exhibited for proline accumulation caused by silicon application rather than such accumulation in stress treatment compared to control. Conclusion: Silicon reduces oxidative damage induced by reactive oxygen species and with the increase in antioxidant enzyme activities caused to protect plants against environmental stresses.  

Abstract Aim: Study of different factors affecting on improvement of growth and development of medicinal plants is very important. Inorganic elements are considered as those affecting factors. The aim of this research was to study the effects of different silicon concentrations on anatomical and developmental characteristics and some growth parameters of borage (Borago officinalis L.) in hydroponic conditions.
Material and Methods: The effects of different concentrations of silicon on anatomical features of epidermis and stomata cells and some growth parameters including quantity of photosynthetic pigments and proline in borage were studied. To this end, a hydroponics experiment was conducted randomly with different amounts of silicon including 0, 0.5, 1, 1.5, 2, 2.5 mM in four replications in greenhouse conditions.
Results: The results showed that 1.5 mM silicon resulted in a significant increase in stomata length and width, and stomatal index in borage leaf comparing with control and other treatments. Also application of 1.5 mM silicon showed positive effects on fresh weight of shoot and total chlorophyll content of plants compared with control. However it seems that silicon in high concentrations had negative effect on growth and anatomical attributes of the plant.
Conclusion: According to study of physiological and anatomical results, positive effects of silicon on pharmaceutical borage are just observed in appropriate and endurable concentrations for the plant.